connecting rod      
noun [ C ]  engineering specialized uk/kəˈnek.tɪŋ ˌrɒd/ us/kəˈnek.tɪŋ ˌrɑːd/ (informal con rod)
 连杆(在引擎中起连接作用,尤指汽车曲轴和活塞之间的连杆)
a rod that joins two particular moving parts in an engine, especially one joining the piston to the crankshaft in a motor vehicle